/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: Jiang Jinxi
 * Date: 2024-03-16
 * Time: 14:02
 */
public class Area {
    public static void main(String[] args) {
        double x1 = 33.7489954;
        double y1 = -84.3879824;
        double x2 = 35.2270869;
        double y2 = -80.8431267;
        double x3 = 32.0835407;
        double y3 = -81.0998342;
        double x4 = 28.5383355;
        double y4 = -81.3792365;
        double AB = Math.sqrt(Math.pow(x1-x2,2) + Math.pow(y1-y2,2));
        double BC = Math.sqrt(Math.pow(x2-x3,2) + Math.pow(y2-y3,2));
        double CD = Math.sqrt(Math.pow(x3-x4,2) + Math.pow(y3-y4,2));
        double DA = Math.sqrt(Math.pow(x4-x1,2) + Math.pow(y4-y1,2));
        double AC = Math.sqrt(Math.pow(x3-x1,2) + Math.pow(y3-y1,2));
        double s1 = (AB+BC+AC)/2;
        double s2 = (CD+DA+AC)/2;
        double area1 = Math.sqrt(s1*(s1-AB)*(s1-BC)*(s1-AC));
        double area2 = Math.sqrt(s2*(s1-CD)*(s2-DA)*(s2-AC));
        System.out.println(area1+area2);


    }

}
